1. Field of the Invention
This invention relates to a wall plug, suitable for fixing a threaded fastener member to a compact architectural member, said threaded fastener member being provided with a head portion defining a seating surface, and said plug being formed by a tubular body portion defining at least one first transverse dimension and comprising: [i] a fore portion provided internally with an orifice for insertion and initial screwing of said threaded fastener member and provided externally with anti-rotation means; [ii] a long central expansion portion, having longitudinal through slots; and [iii] a short rear tail portion for final screwing.
The said compact architectural member may be a wall, either of solid brick, concrete, hollow brick, etc., or a ceiling, or any surface. In turn, the invention relates preferably to a plug made from synthetic plastics material.
2. Prior Art
If these conventional plugs are used for the attachment of a raceway for electrical wiring to a wall, metal structure or other supports, there is the risk that one or more of the cables housed in the raceway may become deteriorated by friction with the head portions of the threaded fastener members and with the washers accompanying them, which may cause short circuits or faults in the electrical circuits.
With a view to avoiding this risk of presumable accident in raceway installations, the solution has been adopted of doing away with the metal washer, relegating its function to the plug, and of making the head portion of the threaded fastener member or screw inaccessible to the cables installed in the raceway.
In accordance with the foregoing solution, the wall plug of the invention has been developed, said plug including a cup for housing completely and loosely said head portion of said threaded fastener member, said cup: being provided with a bottom wall in which said orifice opens for insertion of said threaded fastener member; and having a second transverse dimension larger than said first transverse dimension of said tubular body portion.
According to a preferred feature of the invention, said bottom wall of said cup is provided with a shape mating with said seating surface of said head portion of said threaded fastener member.
Also according to the invention, said cup is provided with removable stopping means.
The invention also contemplates that said cup is an independent body member and separable from said tubular body portion, in which case there are means for coupling said cup to said tubular body portion.